Mirrors

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Chapter 18

• Mirrors Lenses

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Calculate the angle of total internal reflection
in ignoramium(n 4.0)
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Mirrors

• Smooth surfaces that reflect light waves

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Mirrors

• Mirrors have been used for thousands of years by
  polishing metal

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Mirrors

• Mirrors producing sharp well defined images
  were developed by Jean Foucault in 1857

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Mirrors

• Jean Foucault developed a method to coat glass
  with silver making excellent mirrors

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Object

• The source of the spreading light waves being
  observed

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Image

• A reproduction of an object observed through
  lenses or mirrors

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Image

• When you look into a mirror, you see an image of
  yourself

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Plane Mirror

• Mirrors on smooth flat surfaces that give regular
  reflection and good images

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Regular Reflection

• All reflect waves are parallel producing a good
  image

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Diffuse Reflection

• Reflect waves from a rough surface bounce in all
  directions producing a poor or no image

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Objects Images

• Objects images are represented by arrows as to
  distinguish the top from the bottom

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do
di
ho
hi
image
object
di do hi ho
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Virtual Image

• Light rays focus on a point behind the mirror

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Virtual Image

• Virtual images are erect image object pointing
  in the same direction

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Concave Mirrors

• Light rays are reflect from the inner (caved in)
  surface part of a hollow sphere

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Concave Mirrors

• Parallel light rays converge when reflected off
  of a concave mirror

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Concave Mirrors
F focal point
C
F
C center of curvature
Principal axis
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Focal Point

• Point at which parallel light rays converge
  (reflecting from a concave mirror in this case)

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Focal Length (f)

• The distance between the mirror or lens and the
  focal point

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Center of Curvature

• The center of the sphere whose inner surface
  makes the concave mirror

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Concave Mirrors
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Concave Mirrors
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Concave Mirrors
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Concave Mirrors
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Concave Mirrors
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Concave Mirrors
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Concave Mirrors
do gt C di lt do hi lt ho
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Concave Mirrors
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Concave Mirrors
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Concave Mirrors
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Concave Mirrors
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Concave Mirrors
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Concave Mirrors
do C di do hi ho
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Concave Mirrors
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Concave Mirrors
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Concave Mirrors
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Concave Mirrors
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Concave Mirrors
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Concave Mirrors
do lt C di gt do hi gt ho
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Concave Mirrors
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Concave Mirrors
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Concave Mirrors
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Concave Mirrors
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Concave Mirrors
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Concave Mirrors
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Concave Mirrors
do lt f di BM hi gt ho
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Problems with Concave Mirrors
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Draw Ray Diagram Determine Type of Image
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Draw Ray Diagram Determine Type of Image
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Draw Ray Diagram Determine Type of Image
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Draw Ray Diagram Determine Type of Image
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Draw Ray Diagram Determine Type of Image
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Mirror Lens Formula
1 1 1 f do di


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Mirror Lens Formula

• f focal length
• do object distance
• di image distance

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Magnification Formula
hi di ho do

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Magnificaton
hi ho
M
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Magnification Formula
M magnification ho object height hi
image height
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Problems
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A 5.0 cm object is placed 25.0 cm from a concave
mirror with a focal length of 10.0 cm.
Calculatedi, hi, M
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A 250 mm object is placed 25 cm from a concave
mirror whose center of curvature is 250 mm.
Calculatedi, hi, M
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A 15 cm object placed 75 cm from a concave mirror
produces an image 50.0 cm from the mirror.
Calculatef, hi, M
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A 50.0 mm object is placed 0.25 m from a concave
mirror with a focal length of 50.0 cm.
Calculatedi, hi, M
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Convex Mirrors

• Light rays are reflected from the outer surface
  part of a sphere

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Convex Mirrors

• Parallel light rays diverge when reflected off of
  a convex mirror

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Convex Mirrors
do lt f di BM hi lt ho
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Spherical Aberration

• The parallel rays reflected off of the edges of a
  spherical concave mirror miss the focal point,
  blurring the image.

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Spherical Aberration

• This is corrected by using a parabolic concave
  mirror

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Lenses

• Transparent material that allows that light to
  pass through, but refracts the light rays

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Concave Lenses

• Caved in lenses where the center is thinner than
  the edges

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Convex Lenses

• Bulging lenses where the center is thicker than
  the edges

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Concave Lenses

• Parallel light rays diverge when passing through
  a concave lens

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Convex Lenses

• Parallel light rays converge when passing through
  a convex lens

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Convex Lenses
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Convex Lenses
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Concave Lenses
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Chromatic Aberration

• The parallel rays passing through a lens are
  refracted at the edges more so than at the center
  dispersing the colors

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Chromatic Aberration

• Corrected through lens coating or double lens
  effect

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Achromatic Lens

• A lens that has been made so that there is no
  chromatic aberration

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Find the image
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Eye Glasses

• Concave lenses correct nearsightedness
• Convex lenses correct farsightedness

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Nearsighted

• Sees close-up well, but cannot see distances very
  well

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Farsighted

• Sees distances well, but cannot see close-up very
  well

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A 150 cm object placed 75 cm from a concave
mirror produces an image 250 cm from the mirror.
Draw Calculate f, hi, M
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A 250 cm object placed 1.5 m from a convex lens
with a focal length 50.0 cm from the mirror.
Calculatedi, hi, M
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A 350 cm object placed 150 cm from a convex
mirror with a focal length -75 cm from the
mirror. Calculatedi, hi, M
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Draw Ray Diagram Determine Type of Image
Mirror
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Draw Ray Diagram Determine Type of Image
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Draw Ray Diagram Determine Type of Image
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Draw Ray Diagram Determine Type of Image
Mirror
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Draw the Ray Diagram
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Draw the Ray Diagram
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Convex Lenses